19.
• Correct: every requirement given in SRS is a requirement of the software• Unambiguous: every requirement has exactly one interpretation• Complete: includes all functional, performance, design, external interface requirements; definition of the response of the software to all inputs (valid and invalid)• Consistent: internal consistency www.qbi.in

20.
• Ranked importance: essential vs. desirable• Verifiable: for each requirement there must be a “finite cost-effective” method to verify process with which a person or machine can check that the software product meets the requirement.”• Modifiable: SRS must be structured to permit effective modifications (e.g. don’t be redundant, keep requirements separate)• Traceable: origin of each requirement is clear. www.qbi.in